Efficient Virtualization-Based Fault Tolerance

Virtualization technology has been widely adopted to enable elastic IT infrastructure, with improved manageability and increased service reliability. Especially, virtualization technology could provide a unique benefit to protect any legacy application systems from hardware failures. The reliability of virtual machines running on virtualized servers is not only threatened by hardware failures beneath the whole virtual infrastructure, but also nosy hypervisors that essentially support virtual machines cannot be trusted. In this paper, a virtualization-based fault tolerance mechanism using epoch-based (checkpoint-based) synchronization is proposed, and several performance optimization technologies are applied including a non-stop/pipelined, continuously migration, dirty tracking for guest virtual memory/virtual device status, and eliminate data transfer between QEMU and KVM. The experimental results show that these optimizations have greatly saved the processor usage, synchronization bandwidth and have significantly improved VM network throughput and latency at the same time.